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LaSalle Unit 1 and LaSalle Unit 2 have both experienced an automatic reactor scram, in conjunction with a loss of offsite power. This was caused by an apparent lightning strike in the main 345kV/138kV switchyard during a thunderstorm. 138kV line 0112 has been inspected in the field, and heavy damage has been noted on the insulators on two of the three phases on a line lightning arrestor line side. The plant systems have all responded as expected. All five diesel generators started, and have loaded on to their respective buses as designed. All rods went full in on both units during the respective scrams. HPCS (High Pressure Core Spray) system was started on each unit and automatically aligned for injection for initial level control. The MSIVs (Main Steam Isolation Valves) are shut on both units with decay heat being removed via the safety relief valves. Suppression pool cooling is in progress. The licensee will notify the NRC Resident Inspector and has notified the State. Notified DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.

• * * UPDATE FROM DON PUCKETT TO VINCE KLCO AT 2113 EDT ON 4/17/2013 * * *

In addition to information (previously provided), LaSalle Unit 2 received a high drywell pressure signal (1.77 psig) due to loss of containment cooling from the loss of power. At the time of this high drywell pressure signal, high pressure core spray pump and 2B residual heat removal (RHR) pump was already in operation, the low pressure core spray system and 2A residual heat removal system was secured and (placed) in pull to lock. When the signal was satisfied the ECCS (Emergency Core Cooling Systems) signal was processed but only the 2C RHR pump would have started. In this case, the 2C RHR pump tripped when the signal was received. There is no evidence of reactor coolant leakage. There was no additional ECCS systems discharging into the RCS (Reactor Coolant System). As (initially stated), level was controlled using High Pressure Core Spray and level control is now being maintained using the Reactor Core Isolation Cooling (RCIC) systems. The 2C RHR pump trip is under investigation. Due to the initial loss of offsite power for both Unit 1 and Unit 2 reported at 1511 (CDT), multiple containment isolation valves isolated and closed as expected. Once initial containment isolations were verified, two Unit 2 primary containment vent and purge valves were opened to vent the Unit 2 containment. Once Unit Two containment pressure reached 1.77 (psig), these two vent valves isolated as expected. Due to the loss of offsite power, the Station Vent Stack Wide Range Gas Monitor (WRGM) and the Standby Gas Treatment Wide Range Gas Monitor (VGWRGM) also lost power. Manual sampling has been implemented and power is restored to the VGWRGM, however the VGWRGM has not been declared operable yet. Normal radiation levels have been reported from the manual sampling. (This is being reported in accordance with 10CFR50.72(b)(3)(xiii).) The licensee notified the NRC Resident Inspector and the State of Illinois. Notified the R3 IRC, NRR EO(Skeen), IRD MOC (Grant).

• * * UPDATE AT 0057 EDT ON 04/18/13 FROM MIKE LAWRENCE TO S. SANDIN * * *

After the Unit 2 primary containment vent and purge system isolated on the Unit 2 containment High Pressure signal, Venting of the Unit 1 primary containment was commenced. At 2005 CDT, Unit 1 primary containment pressure reached the Group 2 primary containment isolation system setpoint (1.77 PSIG) causing the primary containment vent and purge valves being used to vent the Unit 1 containment to isolate. Unit 1 primary containment venting was being performed through the Standby Gas Treatment system which is a filtered system. In addition to the primary containment isolation signal on high drywell pressure, an ECCS initiation on high drywell pressure also occurred. The ECCS signal resulted in an auto start of the 1C RHR system. The 1B RHR system was already running in suppression pool cooling mode. 1A RHR and LPCS had been secured to prevent overloading the common diesel generator for division 1. The common diesel generator supplies both Unit 1 and Unit 2 division 1 ESF busses. The licensee informed the NRC Resident Inspector. Notified NRR EO (Skeen), IRD MOC (Grant) and R3IRC (Louden).

• * * UPDATE AT 0947 EDT ON 04/18/13 FROM JUSTIN FREEMAN TO PETE SNYDER * * *

LaSalle has terminated the unusual event which was initiated at 1511 on 4/17/13 and reported under EN 48939. This unusual event has been terminated based on meeting the following established criteria. This report is being made in accordance with 10CFR50.72.(c)(1)(iii). 1) Off-site power has been restored to all ESF busses 2) Fuel Pool Cooling has been restored on both units 3) Primary Containment Chillers have been restored on both units 4) Drywell pressure is less than ECCS initiation setpoint 5) ECCS signals cleared to allow diesels to be placed in stand by Recovery of remaining plant systems will be managed through the Outage Control Center (OCC)." The licensee informed the NRC Resident Inspector. Notified R3DO (Orth), NRR EO (Chernoff), IRD (Grant), DHS, FEMA, USDA, HHS, DOE, NICC, EPA, and Nuclear SSA via email.

• * * UPDATE AT 1711 EDT ON 4/21/2013 FROM GREG LECHTENBERG TO MARK ABRAMOVITZ * * *

In addition to the 10 CFR 50.72 Sections initially identified, the Loss of Offsite Power was also reportable under 10 CFR 50.72(b)(3)(v)(D) as an event or condition that could have prevented the fulfillment of the safety function of systems needed mitigate the consequences of an accident. This event is considered a safety system functional failure for both Units 1 and 2. The licensee will notify the NRC Resident Inspector. Notified the R3DO (Orth).

NMP2 inserted a manual reactor scram due to a through wall leak on feedwater pump 2FWS-P1A minimum flow line. 2FWS-P1A has been removed from service to minimize the leak. All control rods inserted and all systems functioned as designed. The unit will remain in hot shutdown until plant startup. All systems functioned as required and the scram was uncomplicated. The licensee plans to issue a press release and has informed the NRC Resident Inspector and the New York State Public Service Commission.

• * * UPDATE AT 1035 EDT ON 8/11/11 FROM MANLEY TO HUFFMAN * * *

The licensee will not be issuing a press release regarding this manual scram. R1DO (Powell) notified.

At 0750 PDT the licensee experienced a turbine trip and reactor scram. At approximately the same time, a fire was detected in the non-safety related 6.9 kV feed bus to switchgear SH-5 and SH-6 in the turbine building. The fire and associated fault to the switchgear feed bus caused a loss of power to both reactor recirculation pumps and the automatic reactor scram. The fire produced smoke and potentially toxic gases. Due to the presence of potentially toxic gas in the power plant, an Unusual Event was declared at 0812 PDT based on EAL 9.3.U.3. At the present time, the fire is out and the smoke is being cleared from the plant. All rods fully inserted upon the reactor scram. Systems functioned as expected except for problems with the EHC system which resulted in the bypass valves remaining open which caused the reactor to depressurize to approximately 390 psi. MSIVs were manually shut to halt the reactor depressurization and cooldown. Decay heat is being removed via relief valves to the suppression pool with reactor pressure being maintained between 500 and 600 psi. Suppression pool cooling is via RHR. Makeup water to the reactor is via normal feed. Licensee is on natural circulation at the time of this report. Normal shutdown electrical alignment is established with the exception of Division II emergency switchgear which is aligned to the backup transformer. A request for assistance was made to the Hanford fire department, however, the fire was out prior to their arrival on site. The licensee has notified State, local agencies and the NRC Resident Inspector.

• * * UPDATE FROM JOHN SLACK TO DONALD NORWOOD AT 1332 ON 08/05/09 * * *

The Unusual Event has been terminated as of 1006 PDT. The licensee is taking the unit to cold shutdown. The licensee will notify the NRC Resident Inspector. Notified NRR EO (Ross-Lee), R4DO (Walker), DHS (Enzer), and FEMA (Eaches).

• * * UPDATE FROM NICK RULLMAN TO PETE SNYDER AT 1827 ON 08/05/09 * * *

Following the reactor scram, with the turbine bypass valves failed fully open, the inboard main steam isolation valves had to be manually closed to prevent excessive cool down. The outboard main steam isolation valves automatically closed from the inability to maintain condenser vacuum. The inability to maintain condenser vacuum was due to limited equipment access in the Turbine Building from heavy smoke. This is reportable under Part 50.72(b)(3)(iv)(A) as a valid actuation of one of the systems listed in Part 50.72(b)(3)(iv)(B)(2). The licensee notified the NRC Resident Inspector. Notified R4DO (Walker).

This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B) RPS Actuation (scram) for Nine Mile Point Unit 2 which states 'Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' On 03/09/2006 at 2214 while operating at approximately 85 % reactor power (coast down to refueling) a condenser low vacuum condition resulted in a turbine trip and a subsequent reactor scram. A loss of sealing steam most probably caused the loss of condenser vacuum and an investigation is in progress. Special Operating procedure N2-SOP-101 C was entered. All control rods inserted (fully) as expected. Condenser vacuum has been stabilized and the main steam isolation valves are open. The plant is stable and recovery actions are in progress. Decay heat is being removed via the turbine bypass valves to the main condenser. The condensate and feedwater system is in operation maintaining reactor vessel level. The electric plant is in a normal shutdown lineup and there was no effect from this transient on Unit 1. The licensee notified the NRC Resident Inspector.

• * * UPDATE AT 0035 EST ON 3/14/06 FROM P. WALSH TO W. GOTT * * *

This update is being made to provide additional information to EN# 42403 which was communicated via ENS on 3/10/06 at 0058 hours. During the scram that occurred at Nine Mile Point Unit 2 on 3/9/06 at 2214 hours, a primary containment isolation signal to RHR Shutdown Cooling, RHR Head Spray and RHR sample valves was received as designed. No components repositioned as the valves are normally closed during plant operations. The licensee will notify the NRC Resident Inspector. Notified R1DO (P. Krohn).